A genomic approach to understanding insecticide resistance in crop pests

了解作物害虫杀虫剂抗性的基因组方法

• 批准号: BB/G023352/1
• 负责人: Christopher Bass
• 金额: $ 85.69万
• 依托单位: Rothamsted Research
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2009
• 资助国家: 英国
• 起止时间: 2009 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FG023352%2F1
• 关键词: genomic; approach; understanding; insecticide; resistance

Insect pests of crops are often controlled using chemical insecticides. Unfortunately over time many pests have evolved resistance to the insecticides used for control. Insects have been shown to develop resistance in two main ways. Firstly by changes in the protein that the insecticide binds to which means that it is no longer as sensitive to the toxic effect of the insecticide and secondly by increased production of enzymes that break down or bind to the insecticide and render it ineffective. In this proposal we aim to study insecticide resistance in two important crop pests the peach potato aphid (Myzus persicae) and the brown planthopper (Nilaparvata lugens). M. persicae is a major pest on a range of crops in the UK and Europe and N. lugens is a major pest of rice crops in Asia, both cause damage to plants through direct feeding and the transmission of viruses resulting in high economic losses. Both of these crop pests have evolved resistance to many of the insecticides used for their control and the main chemical class currently being used is the neonicotinoids. However reports of resistance to this insecticide class have recently been described. Biochemical studies have shown that this resistance is likely to be caused by increased production of enzymes that break down the insecticide, in particular a group of enzymes called cytochrome P450 monooxgenases (P450s). P450s are a class of enzymes with many functions including the breakdown of toxins and insects have been found to have between 46-143 P450 genes, each producing a different enzyme. Insect pests can become resistant to insecticides by increasing the amount of one or more of the P450 enzymes they produce. In this project we aim to examine if resistance in M. persicae and N. lugens to neonicotinoids is caused by over-production of P450s and determine which P450s are involved and why they are over-produced. It is not easy to study the large gene families involved in metabolic resistance however recent advances in the field of genomics (the study of genes and their function) and new associated technologies means that it is now more feasible. This study will exploit these new resources to identify P450 genes in the target pest species. These include the genome (the entire DNA content of an organisms) sequences of a number of insect species (including an aphid), expressed sequence tags or ESTs (small pieces of DNA sequence usually 200 to 500 nucleotides long that are generated by sequencing either one or both ends of an expressed gene) and affordable high-throughput sequencing technologies that allow many hundreds of millions of bases (a unit of DNA) of sequence to be determined in a matter of hours. The identified P450 genes will then be studied using new molecular methods that allow determination of the levels of expression of genes into RNA and protein. The technique RNA interference (the introduction of double-stranded RNA into a cell to inhibit the expression of a gene) will be used to silence P450 genes and therefore examine their role in resistance. Finally the P450 genes will be cloned and expressed as protein to see if they break down or bind to insecticide. When the specific P450s involved in resistance in these crop pests have been identified we will develop diagnostic tools to monitor insect populations for resistance. These are an essential requirement of resistance management strategies which aim to slow or prevent the development of resistance. Prolonging the life of insecticides by managing resistance is vital as there are only a limited number of insecticides available for control and proposed new legislation on pesticides from the European Parliament will dramatically cut the availability of insecticides for use in agriculture. This project will be carried out in collaboration with partners in agrochemical companies and the Insecticide Resistance Action Group to ensure the findings of this study can be rapidly exploited.

农作物的虫害通常是用化学杀虫剂来控制的。不幸的是，随着时间的推移，许多害虫已经对用于控制的杀虫剂产生了抗药性。昆虫已经被证明通过两种主要方式产生抗药性。首先是杀虫剂结合的蛋白质的变化，这意味着它对杀虫剂的毒性作用不再那么敏感，其次是由于分解或结合杀虫剂并使其无效的酶的产生增加。在这项建议中，我们的目的是研究两种重要的农作物害虫--桃蚜(Myzus Persicae)和褐飞虱(Nilparvata Luens)的抗药性。烟粉虱是英国和欧洲多种农作物的主要害虫，褐飞虱是亚洲水稻的主要害虫，两者都通过直接取食和病毒传播对植物造成危害，造成很高的经济损失。这两种作物害虫都对用于控制它们的许多杀虫剂产生了抗药性，目前使用的主要化学类别是新烟碱类。然而，最近出现了对这类杀虫剂产生抗药性的报道。生化研究表明，这种抗药性很可能是由于分解杀虫剂的酶产量增加所致，特别是一组名为细胞色素P450单氧酶(P450)的酶。P450是一类具有多种功能的酶，包括分解毒素和昆虫被发现有46-143个P450基因，每个基因产生不同的酶。害虫可以通过增加它们产生的一种或多种P450酶的数量来对杀虫剂产生抗药性。在这个项目中，我们的目标是检测烟青虫和褐飞虱对新烟碱类化合物的抗性是否由P450的过度产生引起，并确定哪些P450参与其中，以及它们为什么过度产生。研究与代谢抵抗有关的大基因家族并不容易，但基因组学领域(基因及其功能的研究)和新的相关技术的最新进展意味着，现在这一研究更具可行性。这项研究将利用这些新资源来鉴定目标害虫物种中的P450基因。这些包括基因组(生物体的全部DNA含量)、一些昆虫物种(包括蚜虫)的序列、表达序列标签或EST(通过对表达基因的一端或两端进行测序产生的长达200到500个核苷酸的小片段DNA序列)，以及负担得起的高通量测序技术，这种技术允许在几个小时内确定数亿个碱基(DNA单位)的序列。然后将使用新的分子方法对已识别的P450基因进行研究，这些方法可以确定基因在RNA和蛋白质中的表达水平。RNA干扰技术(将双链RNA引入细胞以抑制基因表达)将被用来沉默P450基因，从而研究它们在抗性中的作用。最后，P450基因将被克隆并以蛋白质的形式表达，看看它们是否会分解或与杀虫剂结合。当这些作物害虫中参与抗性的特定P450基因被鉴定出来后，我们将开发诊断工具来监测昆虫种群的抗性。这些是旨在减缓或防止耐药性发展的耐药性管理战略的基本要求。通过控制抗性来延长杀虫剂的寿命至关重要，因为可供控制的杀虫剂数量有限，而欧洲议会提出的关于杀虫剂的新立法将大幅减少农业中使用的杀虫剂的供应。该项目将与农用化学品公司和抗药性行动小组的合作伙伴合作实施，以确保这项研究的结果能够迅速得到利用。

项目成果

Insecticide resistance mediated by an exon skipping event.

• DOI: 10.1111/mec.13882
• 发表时间: 2016-11
• 期刊: Molecular ecology
• 影响因子: 4.9
• 作者: Berger M;Puinean AM;Randall E;Zimmer CT;Silva WM;Bielza P;Field LM;Hughes D;Mellor I;Hassani-Pak K;Siqueira HA;Williamson MS;Bass C
• 通讯作者: Bass C

Investigating the molecular mechanisms of organophosphate and pyrethroid resistance in the fall armyworm Spodoptera frugiperda.

• DOI: 10.1371/journal.pone.0062268
• 发表时间: 2013
• 期刊: PloS one
• 影响因子: 3.7
• 作者: Carvalho RA;Omoto C;Field LM;Williamson MS;Bass C
• 通讯作者: Bass C

Chlorpyrifos resistance is associated with mutation and amplification of the acetylcholinesterase-1 gene in the tomato red spider mite, Tetranychus evansi

• DOI: 10.1016/j.pestbp.2012.05.009
• 发表时间: 2012-10-01
• 期刊: PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY
• 影响因子: 4.7
• 作者: Carvalho, Renato;Yang, Yihua;Bass, Chris
• 通讯作者: Bass, Chris